One Twitter user even pointed out that Mr Trump and his father-in-law are close in age. Mr Knavs is 73 while Mr Trump turns 71 this week.
Scientists have long known that species including birds, mammals and fish pick mates that look similar to their parents. This is known as positive sexual imprinting and it's been shown to play a role in how humans choose a partner.
Scientific studies have shown that, on average, women tend to pick partners whose faces look a bit like their father's.
So while it may make for some amusing Twitter jokes, Melania Trump is certainly not alone in this slightly creepy coincidence.
